Kosmos 60

Kosmos 60 (Russian: Космос 60 meaning Cosmos 60) was an E-6 series probe, launched by the Soviet Union on March 12, 1965. It was the sixth attempt at a lunar soft-landing mission, with a design similar to that of Luna 4. The spacecraft achieved Earth orbit (apogee 287 km, perigee 201 km, inclination 64.8 degrees, orbital period 89 minutes) but failed to leave orbit for its journey to the Moon due to a failure of the power supply in the control system, and was designated Kosmos 60. It had an on-orbit mass of 6530 kg (14,400 lb). The satellite reentered the Earth's atmosphere on 17 March 1965.

Kosmos 60 carried a 16-channel NaI(Tl) scintillator 40 x 40 mm in size. It was surrounded in a charged particle rejection scintillator. The spacecraft weighed 1600 kg and the detector was located inside the vehicle. The detector was sensitive to 0.5-2.0 MeV photons.

Kosmos 60 measured the gamma-ray background flux density to be 1.7×10⁴ quanta/(m²·s). As was seen by Ranger 3 and Lunas 10 & 12, the spectrum fell sharply up to 1.5 MeV and was flat for higher energies. Several peaks were observed in the spectra which were attributed to the inelastic interaction of cosmic protons with the materials in the satellite body.

The designation of this mission as an intended planetary probe is based on evidence from Soviet and non-Soviet sources and historical documents.

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